This invention relates to an integral brake system for motorcycles, comprising a hydraulic brake system acting on one wheel and connected by a hydraulic line to a brake cylinder, which is controllable with a first brake lever, a brake system to which an actuator is assigned acting on the other wheel, said actuator being controllable by the first brake lever as well as a second brake lever, and a regulating device for controlled distribution of the brake force between the two wheels.
With a known integral brake system of this type, the brake system acting on the front wheel and the brake system acting on the rear wheel are both hydraulic. The actuator is assigned to the brake system acting on the rear wheel. The actuator comprises a main brake valve that is connected by separate hydraulic lines to the hand brake lever and the foot brake lever. This main brake cylinder contains a hydraulic control valve which forms the regulating device for controlled distribution of the brake force between the two wheels. With the known integral brake system, it is possible to operate the hydraulic brake system assigned to the rear wheel by using the foot brake lever alone or to operate the hydraulic brake system assigned to both the front wheel and the rear wheel jointly with the hand brake lever. In this case, the regulating system formed by the hydraulic control valve produces a controlled distribution of brake force between the two wheels. However, such a hydraulic regulating device which distributes the brake force to the front and rear wheels in a manner approximating the ideal dynamic brake distribution is extremely complex and expensive. In practice, it has been found that a seemingly ideal distribution of the dynamic brake force to the front and rear wheels cannot be achieved with a purely hydraulic control valve.
The object of this invention is to create a generic integral brake system for motorcycles which will permit an optimum distribution of the dynamic brake force between the front wheel and the rear wheel at a low manufacturing cost.
According to this invention, an integral brake system that conforms to these requirements is characterized by an electronic control unit that contains the regulating device and is connected by electric control lines to a sensor that responds to operation of the hydraulic brake system and to the actuator and the second brake lever, whereby the control unit controls the actuator as a function of the output signal of the sensor or in the case of operation of the second brake lever, to activate the brake system acting on the second wheel. In the case of the inventive integral brake system, the actuator replaces the main brake cylinder comprising the hydraulic control valve and a hydraulic control is dispensable.
The sensor that responds to operation of the hydraulic brake system may detect, for example, the actuation path of the first brake lever or the opposing force exerted on it. However, the sensor could also detect the deceleration of the motorcycle. A sensor that detects the pressure in the hydraulic line is particularly advantageous.
An anti-skid function may also be implemented on both wheels using the inventive integral brake system. To this end, an anti-skid sensor is provided for each of the two wheels; this sensor is connected to the control unit by control lines and a pressure reducing device upstream from the pressure sensor is provided in the hydraulic line and is connected by a control line to the control unit.
With the inventive integral brake system the brake system acting on the second wheel may be operating by both hydraulic and mechanical means. In the first alternative, the actuator is designed as a pump and is connected to the brake system by a hydraulic line. In the second alternative, the actuator is an electric motor actuator which is mechanically connected to the brake system. The integral brake system is preferably designed so that both the brake system assigned to the front wheel and the brake system assigned to the rear wheel can be operated with the hand brake lever whereas only the brake system assigned to the rear wheel can be operated with the foot brake lever.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.